The Rack Extensions "Set Vca" includes four stereo modules which through Know or Cv Input control the volume of the related Audio Outputs from 0 to 127. These values are exactly those used by the Reason Rack classics such as the "Line Mixer 6: 2" or the "Mixer 14: 2". Very useful is the possibility of displaying these values also in dB so that you can interact with Racks that have control only in dB. Combined with the Rack Exensions "Set Program" (found in the shop) you can make many volume settings (controlled by a single command) which are particularly useful in Reason live performances. The vca that are not used or have value=0 (Inf dB), do not consume resources because the inputs and outputs are disabled.